Sequence comparisons of three wild-type Bronze-1 alleles from Zea mays

Abstract

We have sequenced genomic clones of two wild-type Bronze-1 (Bz1) alleles, and a cDNA clone from a third wild-type Bz1 allele from maize. Two overlapping transcripts initiate at least 250 bp apart. The first AUG codon after the shorter and more abundant transcript cap site(s) begins the longest open reading frame. The transcript is preceded by a putative TATA box, but not a recognizable CAAT box. The bz1 gene contains a single intron, and exhibits a strong bias for codons with the highest G+C content. Sequence polymorphisms among the Bz1 alleles include deletions/additions, a transposable element insertion, and single base pair substitutions.

Identification of a Bifunctional Maize C- and O-Glucosyltransferase

“…First, we evaluated how genes of candidates were expressed in different maize tissues and whether they are regulated by the P1 transcription factor, extensively known to be involved in the regulation of C-glycosyl flavone biosynthesis (16,(37)(38)(39). Therefore, we built a list of 157 putative UGTs in maize using bronze1 (GRMZM2G165390), one of the best studied maize UGTs and one involved in anthocyanin biosynthesis (40,41), as a starting point. We next intersected this list with RNA sequencing data publicly available from maize leaves, shoots, and roots from the B73 inbred line and RNA sequencing data from silks and pericarps with contrasting P1 alleles in the common A619 genetic background and referred to here as P1-rr and P1-ww (supplemental Fig.…”

“…Although flavonoid glycosides have been described in maize, for example the characterization of a glycosyltransferase involved in anthocyanin biosynthesis (bronze1), information about other glycosyltransferases implicated in flavonoid metabolism have not been reported (40,41). Here we have characterized a maize glycosyltransferase, UGT708A6, involved in the biosynthesis of C-glycosyl flavones by in vitro and in vivo bioconversion activity assays.…”

The highly recombinogenic bz locus lies in an unusually gene-rich region of the maize genome

“…The region contains two previously characterized genes: bz, encoding UDPG-flavonoid 3-O-glucosyl transferase (UF3GT) (13,19) and stc1, encoding a sesquiterpenoid cyclase (14). In the bz-m2(Ac) mutant, the transposon Activator (Ac) is inserted in the second exon of the gene (13,20).…”

“…bz. The bz gene has been characterized previously (13,19). It consists of two exons and encodes a 471-aa protein (UF3GT).…”

The UDP-glucose:p-Hydroxymandelonitrile-O-Glucosyltransferase That Catalyzes the Last Step in Synthesis of the Cyanogenic Glucoside Dhurrin in Sorghum bicolor

“…A larger set of functionally verified glucosyltransferase-encoding cDNAs are required to further our understanding on this matter, which may not be confirmed until the three-dimensional structure of a secondary plant metabolism glucosyltransferase has been presented. sbHMNGT shares highest degree of overall identity with a putative glucosyltransferase deduced from an unknown clone from P. sativum, a Z. mays flavonoid-glucosyltransferase (43), and a Z. mays indole/acetic acid-glucosyltransferase (39) ( Table I). This illustrates that the large number of putative glucosyltransferase-encoding cDNAs tabulated in the nucleic acid data banks, which have been labeled as flavonoid or indole/acetic acid-glucosyltransferase homologues, may be expected to glucosylate a range of other substrates in vivo and thus to be functionally mislabeled at present.…”